Etching machine



Sept. 29, 1931.

F. T. POWERS ETCHING MACHINE Filed April 22, 1950 \NVENTOR Patented Sept. 29', 1931 PATENT OFFICE FRANK '1. POWERS, OF DOUGLASTON, NEW YORK E'IGHING MACHINE Application filed April 22,

This invention relates to improvements in apparatus for use in etching the surfaces of metal objects and particularly for the etching'of metal plates used in the preparation of halftones and line cuts used. in printing.

One object of my invention is to provide an apparatuswhich is faster to operate and which possesses a greater convenience of operation than those formerly in use,' and one which is: free from some of the objectionable features of the older forms of etching ma chines. In referring to the older or previous forms of etching machines I refer more particularly to those forms now in very general use in the photo-engraving industry which consist essentially of a chamber or receptacle for the etching fluid and a rotary sprayer of suitable form within the chamber for spraying the etching fluid against the plate being so etched. Such etching machine-sare referred to herein as etchers of the chamber type. In those forms of etching machines of the chamber type previously in use it is usually necessary to insert and remove the object to be etched through the top or cover of the chamber. This makes it necessary for the operator to bend over the machine and thereby expose him-self to the inhalation of noxious gases which rise from the open machine. My 30 new form' of etching machine entirely eliminates this objectionable feature.

Another advantage possessed by this new etching machine lies in the ease and convenience with which the object to be etched may be withdrawnfrom the etching chamber for examination. With the etching machines of the usual types it is necessary for the operator to remove the object being etched from its position within the etching chamber by hand. This necessitates the wearing of rubber gloves or other suitable protection on the hands of the operator, otherwise the bare hands would come in contact with the etching fluid and gases within the etching chamber and'so be exposed tothe action of the said'fluid and gases. This frequent contact of the hands of the operator with the etching fluid and gases results in marked and conspicuous discolouration of the skinand at times even in soreness, unless the hands are protected. By the use 1930. Serial N0. 446,394.

of my invention all contact with the etching fluid and gases is avoided and no protection to the hands is required. Another important advantage possessed by this invention lies in the fact that the object being etched is withdrawn from the machine directly into a positionmost convenient for the operator to examine it carefully and minutely without having to touch the object or alter its position. The examination of a 60. half-tone plate at intervals during the progress of the etching operation is often desirable. For the purpose of making a minute and careful examination of the plate the operator usually uses a magnifyingglass. With 05. the older types of etching machines, it is necessary for the operator to remove the plate from the etching chamber, clean off the acid by washing with water, then place the plate on some convenient support outside of the 10 etching machine for examination. At the conclusion of the examination, if additional etching is deemed by the operator to be necessary, the plate is again placed within the etching chamber, the cover of the machine closed and the etching continued.

With a machine of my new type the simple movement of the traveling carriage serves to bring the. plate out of the etching chamber and into a position most convenient for careful examination with a magnifying glass. This saves time and is more convenient.

Still another advantage possessed by this invention is the saving in time made possible by the fact that the etching action may be stopped and started instantly by the simple movement of a lever from one position to another without waiting for the sprayproducing element to come to rest after being in rapid rotation or waiting for it to get up to speed after being at rest. The starting and stopping of the rotatable spray-producing element in etching machines of this type is a time consuming operation and takes severalseconds to accomplish each time the operation of starting or stopping is necessary. With my invention in use this time is saved each time it is necessary to withdraw the object being etched from the etching chamber for observation or examination.

The various features of the invention and its advantages will be more fully understood by reference to the accompanying drawings and will be set forth in the description and the claims. l

In the drawings, Fig. 1 represents in perspective a general view of the complete machine. Fig. 2 represents a sectional view taken through the etching chamber and Fig. 3 represents a sectional view taken through the machine ust outside of the etching chamher.

In the several figures like symbols are used to designate the same or similar parts, and arrows indicate direction of movement or rotation. In Fig. l a receptacle 1. of material resistant to the action of the etching fluid is shown mounted on a suitable framework 2. so as to bring: it to a convenient working level above the floor. lVithin the receptacle near one s de is a paddle wheel 3 of suitable design mounted on a shaft 4 which is provided with bearings not shownl of the usual type. attached to and supported by the framework 2. (ln one end of the shaft is rigidly ke ed a pul ey 5. which receives a belt or other suitable driving: means connectine; with motor or other suitable sou ce of power not shown in the drawings. The pulley 5 and with it the paddle wheel. 3 is rotated in the direction indicated by the arrow when power is applied. On the end of the shaft 4 ad acent to that occupied by the pulley 5 is rieidlv keyed another pulley 6 by mean of which power is transmitted through a belt 6/: to a an 6?) which is located near the top of the receptacle within a suitable housino: 8. The suc ion s de of this fan housino: is o en to the inte ior ot the receptacle l throuoh an oneninrr 9 and the discharere side of the tan housine' is connected with a due or duct 10 leading" to a safe point of discharc'e. such as through the root ot the building in hich the machine is located. O er the rotatine padd e whee is pivotallv mou ted a hatlie ll. n eter hlv o curved section. which ma be rotated about its ivotal oint b means of a sha t assino throu rh one side oi the receptac e 1 and rov ded with lever or h ndle 13 A'iIiTQPlWnE! a flfi lever or handle 13 is a l l'llietolllf weir ht 14- monnted in uch a manner that when the haiile plate 1 s n its uppermost pos tion a shown by the ful nes n ire 2. he c ht will he on that sid ot a ver cal lane throueh the cen re o otation ot he baffle, wh ch will tend to ho d the h t n i u perinost position. On po i e s d o e ontaclo 1 are 'nlaoorl sto s 1?; w ir limit. the unwardtravel o the h i ll. a ther pai of stops l6 are pla d o limit the down a d trave oi the ba tle ll at such a point that the bat le p ate ll n he lowe ed to an extent that will brine it into contact with the rotating paddle wheel At the end of the receptacle 1, opposite to that near which the paddle wheel is located is rigidly mounted a track 17, which extends across the receptacle and passes through the lower portion of an opening 18 in the side of the receptacle. Above this track 17 and at the top of the receptacle is a guide bar 19 which is parallel with and of a length approximately equal to that of the track 17. A travelling carrier 20 is provided with two wheels 21 suitably mounted, which engage and roll upon thetrack l7, and said carrier is held in vertical position by means of two guides 22 so placed that they engage loosely the guide bar 19. Along the lower edge of the travelling carrier is provided a projecting ledge 23. upon which may be placed in a slightly backwardly inclined position the plate to be etched. On each side of the travelling carrier 2-0 are provided plates 24 and 25 of such size and shape that when the travelline; carrieris in its extreme position within the r ccptacle, plate 24 will cover and close the opening; 18. and when the travelling carrier is in its extreme position outside of the receptacle the plate 25 will cover and close the opening; 18. Under that portion of track 17 which is external to the receptacle, is mounted a tray 26 of liquid-tight construcand provided in its bottom with a drain pipe 27 which leads to any suitable discharge, point such as a sewer. Over the upper guide bar 19 is located apertorated spray pipe 28 connected to a suitable water supply by means of a pipe 29. The valve 30 in the supply duct leading: to the perforated spray pipe 28 permits control of the water admitted to the spray pipe 28. The perforations in the spray pipe 28 are located on the under side in such a position that water emerging from them when the valve 30 is opened, is directed down ward upon the obiect beingetched when the travelling); carrier 20 is in its extreme position without the receptacle.

Having" described the construction of one embodiment of my invention. I will now de scribe its method 0t operation.

Before beginning): the etching: of an object the receptacle 1 is filled with a suitable etching fluid up to a level such that the paddles or blades of the paddle wheel 3 will dip into the fluid as the paddle wheel is revolved by means or" the pulley 5 driven by any suitable source or power by means of the belt. The travelling carrier 20 is rolled out on the traclt 17 to its GYtI'GB'lO position outside of the receptacle 1 and the plate or other obi act to be etched is placed upon the carrier. The carrier is then rolled in on the track 1'? to its extreme posit on within the receptacle, in which position of the carrier the plate 24 closes up the openine; 18 in the side of the receptacle so that none of the etching fluid can escape from the interior of the receptacle during the etchino;

process. The baffle plate 11 is placed in its lower position within the receptacle by means of the lever or handle 13 and rests against the stops 16. In this position of the baffle plate and of the lever 13 the weight M will act to hold baffle plate in its lowered position even when the etching fluid is forcibly projected against the underside of the baffle plate by the action of the paddlewheel 3. Power is then applied to rotate the shaft 4, which causes the paddle wheel 3 and the fan 66, through the belt 6a, to rotate in the direction indicated by the arrows. As the result of this rotation the etching fluid is picked up by the paddle wheel 3 and forcibly projected in minute drops or a spray against the battle plate, and at the same time the fan 6?) forces gases from within the receptacle out through the duct 10, so preventing'any of the noXious gases from within the receptacle escaping into the room in which the etching operation is carried on. All being now in readiness for etching, the baffle plate is raised from its lower to its upper position against the stops 15 by means of the lever or'handle 13, and is held in that position by the action of gravity on the weight '14-. The baflie plate is now out of the line of movement of the spray projected by the paddle wheel toward the ob iect to be etched and the spray strikes the object and etching begins. The operation of etching is continued for a predetermined period of time or until in the operators opinion the etching has progressed far enough. The bafiie plate 11 is again returned to its lower position against the stops 16, in which position it completely intercepts the spray projected toward the object being etched and so instantly stops the etching action without shutting off the source of power or waiting for the paddle wheel to come to rest as is necessary with other types of etching machines. The carrier 20 is then moved out of the receptacle along the track 17 to its outermost position. WVith the carrier in this position the plate 25 closes the opening 18 in the side of the receptacle 1 so that no gases from within the receptacle can escape. By opening the valve 30 water is admitted to the perforated spray pipe 28 and issues from the perfora-' tions down on and flows over the object be ing etched and so flushes off the etching fluid remaining on or adhering to it. The object is then in readiness for examination by the operator and in a most convenient position for such examination .without having been touched by the operator and without any of the etching fluid having come into contact with the operator. After examination the object may be returned to the interior ofthe etching chamber by simply sliding the carrier along the track 17 until it is again in its extreme position within the etching chamber, or the etched object, washed free from all etching fluid, may be removed from the carrier. It will be noted that these operations are capable of rapid" performance. The simple movement of the handle 13 starts and stops the etching action of the spray by inter- 'cepting the spray between the paddle wheel and the object being etched without waiting for, the paddle wheel togetup to speed in starting or to'come to rest when stopping as is the case with etching machinesnow in common use. Nor is it necessary for the operator at any time to touch the object being etched either to enter it into or to withdraw it from the etching chamber. Nor does the operator atany time come in contact with the etching I am well aware that many forms of etch ing machines of the chamber type are in use and that many of the features or components of my machine are not new, and I w1ll,therefore, confine my claims of novelty to those ,7

combinations of parts and to those elements which I believe to be new and novel and for which I desire to secure Letters Patent.

I claim:

1. A machine for etching photo-mechaniwithin the receptacle, said support being provided with closure members whereby the said 1 opening is covered when said support is in its extreme positions within or without the receptacle, substantially as described.

2. A machine for etching photo-mechanical printing plates, of the type having a receptacle for the etching fluid, a support for the plate to be etched, and means for spray ing the etching fluid against the plate, which is characterized by having an opening in one of the upright sides of the receptacle, through which the said support upon which the plate rests in a substantially vertical position is movable to position the plate for etching within the receptacle, and a movable spray I intercepting member, whereby the projection of the spray against the plate may be completely intercepted.

3. In a machine for etching photo-mechanical printing plates the combination of a re- Y ceptacle for the etching fluid having an opening in one of its upright sides through which opening a movable support for the plate to be etched is slidable in and out of the receptacle, said'support being provided with members which eiiect a closure of said opening in the receptacle when said support is in its extreme position within or without the receptacle, and means for spraying the etching fluid against the plate to be etched. 4. In a machine for etching photo-mechanical printing plates the combination of a receptacle for the etching fluid having an opening in one of its upright sides, a support for holding the plate to be etched in a substantially vertical position movable in and out of said receptacle through said opening, and provided with a closure whereby the said opening is closed when the support is positioned Within the receptacle, and means for spraying etching fluid against the plate.

Signed at Douglaston, in the county of Queens and State of New York.

FRANK T. POWERS. 

